• Download the fundus image.
• Open it using File / Open, zoom to half size with Zoom / 1/2.     
• Open the Circle Tool with Tools / Circle, click Image and Circle On, to show the tool on the Fundus Image.  Change the tool color to dark red - this makes the circle tool more visible on this image when adjusting its position or size.  Use *Circle Tool* / Display / Set Tool Color / Dark Red.  Move the Circle by dragging the center handle.  Adjust its size by dragging the handle on the circle (other end of the radial line).  Making the circle roughly the size of the optic disc makes positioning easier.  Once this is done, the image should look like this:

• To take profiles along a ring that is .75 disc diameters off the optic margin, adjust the radius of the circle to be 2.5 larger than what it was.  You can do this manually by noting the radius in the Tool Window

and adjusting the radius accordingly, or by using Profiles / Set Ring Radius / Times X / 2.5.

• The image should now look like this:

• For more room for plots in this illustration, I am using a smaller circle:

I moved the outer handle so that the radial line is horizontal.  This is just to show where profile data starts - at this handle, going counter clockwise around the circle.  Profile data always starts at this 3 O'Clock position, no matter the angular position of this handle.

• Profiles / Profile Plots - Circular / Intensities yields this plot.

Image intensities are multiplied by the scale factor you type in, and plotted radially, with zero being the circle.

• Profiles / Profile Plots - Linear / Intensities gives this:

• Change name of plot using Change Name in the Lispix Menu Bar.
• If resized or covered, use Redraw in the Menu Bar to see all the points.
• Change size by dragging edges or corners.  Zoom by clicking on plot, then using Navigator / Make.
• Values from any plot such as this one can be saved to a text file:  Menu Bar / Plots / Save Plot Text File.
• Profiles / Make Mask makes a binary image ("mask" in Lispix) showing the pixels accessed by the profile tool as white.  To see them superimposed on the fundus image:
  • Open the 2 & 3 Variable Tool
  • Click on the fundus image, then click on Red / X and Green / Y.
  • Click on the mask image, then click on Blue / Z.

   The tool should then look like this:

• Use RGB Overlay / Make RGB Overlay, zoom the image x4, click No Scroll to make it Drag To Scroll, and scroll the image by dragging with the mouse, to see the pixels of part of the ring:



• The blue pixels are those in the profiles.
• You can zoom the findus image and scroll it to see the same place.  Note that the ring does not show the pixels in this way.



• The two images can be scrolled to exactly the same place using the Groups Tool.  I just did it by eye here.

• Profiles / Save Profile as Text / Values saves the intensities in a text file:

•  All of the text files can be imported into Excel*.

  Here is Profiles / Save Profile as Text / Vals & Coords , after opening in Excel:



In my version of Excel, I opened Excel, used the Open menu changing the file type to "Text Files".  The delimited button was the default - so I just clicked "Finish".

• To see statistics on the profile, use Profiles / Profile Statistics:

Lispix opens this text window, and prints the data into it.  It can be copied and pasted directly into Excel:

where I have widened column A.

"Int Abs Dif" stands for Intensity - Absolute value of successive Differences.  The first value should be the absolute value of the difference of intensities between the first and second pixel in the ring (starting at 3 O'Clock and going counter clockwise.)  There is one fewer value in this profile than in the intensity profile.  You can plot this profile using: Profiles / Profile Plots - Circular / Abs Diffs / Scale factor of 5.

or using Profiles / Profile Plots - Linear / Abs Diffs: